Thank You for an excellent podcast. It has inspired me to start off my own group on the classic traveller adventure book 4, Leviantan.

This post replaces my previous post, amending a number of errors and faulty reasoning as a result.To support me in my own game mastering hobby I have written some homemade software. It was while doing this I noticed that hydrogen is quite light and therefore not a very good rocket propellant.Following my amended example below I now think it could very well be achievable by the Tech Level for the Heplar drives.

A good rocket propellant is ejecting a lot of mass or exhausting it at very high velocity or both. Please bear with me for the following example, based on the unofficial but public Leviathan TNE-stats (http://www.downport.com/bard/bard/sara/sara7030.html): A game turn in Brilliant Lances is 30 minutes so I’ll assume the exhaust rate to be 2×112.5 m³ per hour per g. [1 g=9,81 m/s²]. To accelerate the fully loaded merchant cruiser Leviathan (14673250 kg) at 4 g by ejecting propellant at a mass rate of 112.5×2×4 times the density of the propellant, per hour. Assuming for this example that the density of the ejected matter is the same as liquid hydrogen i.e. about 70 kg/m³. This rocket ejects 63000 kg per hour to accelerate its initial mass of 14673250 kg at a rate of 4 g. This requires that amount of mass to be ejected at speed of 395192 m/s or 0,13 % of the speed of light.